[DE-1032] support vector index

[rashtao]

Note

Add vector index support across collection APIs with new options/params, wire-up in internals, tests, and Docker flag to enable the experimental feature.

• Core API:
  • Add ensureVectorIndex(Iterable<String> fields, VectorIndexOptions options) to ArangoCollection and ArangoCollectionAsync.
• Entities/Models:
  • Extend IndexType with vector.
  • Add VectorIndexParams (metric, dimension, nLists, factory, defaultNProbe, trainingIterations).
  • Add VectorIndexOptions (fields, params, parallelism, sparse, storedValues) and hook into OptionsBuilder.
  • Update IndexEntity to expose params; adjust equals/hashCode.
• Internal wiring:
  • Implement request builder createVectorIndexRequest(...) in InternalArangoCollection and invoke from sync/async impls.
• Tests:
  • Add sync/async functional tests for creating and fetching vector indexes.
• DevOps:
  • Enable experimental vector indexes via --all.experimental-vector-index=true in docker/start_db.sh.
• Docs/Javadoc:
  • Minor Javadoc link formatting and deprecation text cleanups.

^{Written by Cursor Bugbot for commit 436690e. This will update automatically on new commits. Configure here.}

[sonarqubecloud]

Quality Gate failed

Failed conditions
55.3% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud